Such dispensing bodies are sometimes called spouts, aperture plates, nozzle arrays, dosing apertures, orifice plates, vibratable membranes, atomizer, vibrating plate, dosing aperture arrangements, aerosol generators and the like. Such terms are hence to be understood as being interchangeable throughout the present document.
In fact such dispensing bodies and liquid dispensing devices are well known. For example see the document EP 1 129 741 in the name of the present Applicant. This document describes a dispensing device for spraying liquid and has a top substrate formed of a main body and of a nozzle body. The nozzle body contains a nozzle array of liquid droplet outlet means allowing a liquid substance contained in the liquid droplet spray device to exit the device, in this case as a spray of droplets. A piezoelectric actuator is used to cause the liquid to undergo a vibration so as to generate the droplet spray.
Generally, such piezoelectric actuator is driven so as to oscillate at or near an appropriate frequency to improve energy efficiency.
The document EP 1 043 162 describes an inkjet apparatus having a liquid detection method using an infrared detector to determine if liquid has passed through a spray path or not. Control means are provided to adjust the spraying itself.
The document US 2007/0216256 describes a drive control circuit for a piezoelectric activated pump. By measuring the internal impedance of the piezoelectric actuator, it is possible to control the operation frequency.
Document US2003/0146300 describes a nebulizer for nebulizing a substance and a reservoir having a metering chamber arranged so as to feed a substance to be nebulized from the nebulization device and a second chamber arranged to hold and retain any of this substance in excess of the volume held in the metering chamber. The device allows detecting the ejection of a unit dose.
However, a simplified and reliable controlled activation and deactivation of the actuator would be useful if the actuator could function by itself so as also to detect dispensing conditions and to control and/or monitor liquid dispense actuation.
It is, therefore, an object of the present invention to provide an innovative dispensing device that overcomes the inconveniences and limitations presented by the prior art documents.
Thus, the present invention concerns a dispensing device fulfilling these objectives efficiently which may be obtained in a relatively simple and inexpensive manner, as defined in the appended claims. The device is further capable of indirectly triggering and monitoring itself.
Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.